JPH0788377A - Waste gas purifying material and method for purifying waste gas - Google Patents

Waste gas purifying material and method for purifying waste gas

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Publication number
JPH0788377A
JPH0788377A JP5259126A JP25912693A JPH0788377A JP H0788377 A JPH0788377 A JP H0788377A JP 5259126 A JP5259126 A JP 5259126A JP 25912693 A JP25912693 A JP 25912693A JP H0788377 A JPH0788377 A JP H0788377A
Authority
JP
Japan
Prior art keywords
exhaust gas
catalyst
oxide
weight
purifying material
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP5259126A
Other languages
Japanese (ja)
Inventor
Akira Abe
晃 阿部
Akira Muramatsu
暁 村松
Kiyohide Yoshida
清英 吉田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Riken Corp
Original Assignee
Riken Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Riken Corp filed Critical Riken Corp
Priority to JP5259126A priority Critical patent/JPH0788377A/en
Publication of JPH0788377A publication Critical patent/JPH0788377A/en
Pending legal-status Critical Current

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  • Catalysts (AREA)
  • Exhaust Gas Treatment By Means Of Catalyst (AREA)

Abstract

PURPOSE:To obtain a waste gas purifying material capable of efficient removal of NOx from waste combustion gas contg. NOx and more oxygen than oxygen reacting theoretically with unconbusted components such as CO, hydrogen and hydrocarbon. CONSTITUTION:This waste gas purifying material has a 1st catalyst obtd. by carrying 0.2-15wt.% silver or silver oxide and 0.01-2wt.% copper oxide on a porous inorg. oxide on the waste gas inflow side and a 2nd catalyst obtd. by carrying 0.02-5wt.% gold as active seed on a porous inorg. oxide on the waste gas outflow side. Hydrocarbon and/or an oxygen-contg. org. compd. is added as a reducing agent to waste gas and NOx in the waste gas is reduced.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は窒素酸化物と過剰の酸素
を含む燃焼排ガスから、窒素酸化物を効果的に除去する
ことのできる排ガス浄化材及びそれを用いた浄化方法に
関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purification material capable of effectively removing nitrogen oxides from a combustion exhaust gas containing nitrogen oxides and excess oxygen, and a purification method using the same.

【0002】[0002]

【従来の技術及び発明が解決しようとする課題】自動車
用エンジン等の内燃機関や、工場等に設置された燃焼機
器、家庭用ファンヒーターなどから排出される各種の燃
焼排ガス中には、過剰の酸素とともに一酸化窒素、二酸
化窒素等の窒素酸化物が含まれている。ここで、「過剰
の酸素を含む」とは、その排ガス中に含まれる一酸化炭
素、水素、炭化水素等の未燃焼成分を燃焼するのに必要
な理論酸素量より多い酸素を含むことを意味する。ま
た、以下における窒素酸化物とは一酸化窒素及び/又は
二酸化窒素を指す。
2. Description of the Related Art Excessive amounts of combustion exhaust gas discharged from internal combustion engines such as automobile engines, combustion equipment installed in factories, household fan heaters, etc. Nitrogen oxides such as nitric oxide and nitrogen dioxide are contained together with oxygen. Here, "containing excess oxygen" means containing more oxygen than the theoretical oxygen amount necessary to burn unburned components such as carbon monoxide, hydrogen, and hydrocarbons contained in the exhaust gas. To do. Moreover, the nitrogen oxide in the following refers to nitric oxide and / or nitrogen dioxide.

【0003】この窒素酸化物は酸性雨の原因の一つとさ
れ、環境上の大きな問題となっている。そのため、各種
燃焼機器が排出する排ガス中の窒素酸化物を除去するさ
まざまな方法が検討されている。
This nitrogen oxide is considered to be one of the causes of acid rain and is a serious environmental problem. Therefore, various methods for removing nitrogen oxides in exhaust gas discharged from various combustion devices have been studied.

【0004】過剰の酸素を含む燃焼排ガスから窒素酸化
物を除去する方法として、特に大規模な固定燃焼装置
(工場等の大型燃焼機等)に対しては、アンモニアを用
いる選択的接触還元法が実用化されている。
As a method for removing nitrogen oxides from combustion exhaust gas containing excess oxygen, a selective catalytic reduction method using ammonia is used, particularly for large-scale fixed combustion devices (large combustors such as factories). It has been put to practical use.

【0005】しかしながら、この方法においては、窒素
酸化物の還元剤として用いるアンモニアが高価であるこ
と、またアンモニアは毒性を有すること、そのために未
反応のアンモニアが排出しないように排ガス中の窒素酸
化物濃度を計測しながらアンモニア注入量を制御しなけ
ればならないこと、一般に装置が大型となること等の問
題点がある。
However, in this method, ammonia used as a reducing agent for nitrogen oxides is expensive, and ammonia is toxic, so that unreacted ammonia is discharged so that nitrogen oxides in exhaust gas are not discharged. There are problems that the amount of ammonia injection must be controlled while measuring the concentration and that the apparatus is generally large.

【0006】また、別な方法として、水素、一酸化炭
素、炭化水素等のガスを還元剤として用い、窒素酸化物
を還元する非選択的接触還元法があるが、この方法で
は、効果的な窒素酸化物の低減除去を実行するためには
排ガス中の酸素との理論反応量以上の還元剤を添加しな
ければならず、還元剤を多量に消費する欠点がある。こ
のため非選択的接触還元法は、実際上は、理論空燃比付
近で燃焼した残存酸素濃度の低い排ガスに対してのみ有
効となり、汎用性に乏しく実際的でない。
[0006] As another method, there is a non-selective catalytic reduction method for reducing nitrogen oxides by using a gas such as hydrogen, carbon monoxide or hydrocarbon as a reducing agent, but this method is effective. In order to reduce and remove nitrogen oxides, it is necessary to add a reducing agent in an amount equal to or larger than a theoretical reaction amount with oxygen in exhaust gas, and there is a drawback that a large amount of reducing agent is consumed. Therefore, the non-selective catalytic reduction method is practically effective only for the exhaust gas having a low residual oxygen concentration that is burned in the vicinity of the theoretical air-fuel ratio, and is not versatile and impractical.

【0007】そこで、ゼオライト又はそれに遷移金属を
担持した触媒を用いて、排ガス中の酸素との理論反応量
以下の還元剤を添加して窒素酸化物を除去する方法が提
案された(たとえば、特開昭63-100919 号、同63-28372
7 号、特開平1-130735号、及び日本化学会第59春季年会
(1990年)2A526、同第60秋季年会 (1990年)3L420、3L42
2 、3L423 、「触媒」vol.33 No.2 、59ページ、1991年
等) 。
Therefore, there has been proposed a method for removing nitrogen oxides by adding a reducing agent in an amount equal to or less than a theoretical reaction amount with oxygen in exhaust gas by using zeolite or a catalyst supporting a transition metal thereon (for example, a special method). Kaisho 63-100919, 63-28372
No. 7, JP-A-1-130735, and 59th Annual Meeting of the Chemical Society of Japan
(1990) 2A526, 60th Autumn Meeting (1990) 3L420, 3L42
2, 3L423, "Catalyst" vol.33 No.2, page 59, 1991 etc.).

【0008】しかしながら、これらの方法では、窒素酸
化物の除去温度領域が狭く、また、水分を含み、運転条
件によって温度変化の大きい排ガスでは、窒素酸化物の
除去率が著しく低下することがわかった。
However, it has been found that these methods have a narrow temperature range for removing nitrogen oxides, and that the exhaust gas containing water and having a large temperature change depending on operating conditions has a significantly low nitrogen oxide removal rate. .

【0009】したがって、本発明の目的は、固定燃焼装
置および酸素過剰条件で燃焼するガソリンエンジン、デ
ィーゼルエンジン等からの燃焼排ガスのように、窒素酸
化物や、一酸化炭素、水素、炭化水素等の未燃焼分に対
する理論反応量以上の酸素を含有する燃焼排ガスから、
効率良く窒素酸化物を除去することができる排ガス浄化
材及び排ガス浄化方法を提供することである。
Therefore, an object of the present invention is to remove nitrogen oxides, carbon monoxide, hydrogen, hydrocarbons, etc., such as combustion exhaust gas from a fixed combustion device and a gasoline engine, a diesel engine, etc. that burn under an excess oxygen condition. From the combustion exhaust gas that contains more than the theoretical reaction amount of oxygen for unburned components,
An exhaust gas purifying material and an exhaust gas purifying method capable of efficiently removing nitrogen oxides.

【0010】[0010]

【課題を解決するための手段】上記課題に鑑み鋭意研究
の結果、本発明者は、多孔質の無機酸化物に銀銅成分と
金成分をそれぞれ特定量担持してなる排ガス浄化材、あ
るいは多孔質の無機酸化物に銀銅成分と金成分及びPt等
の成分をそれぞれ担持してなる排ガス浄化材を用い、排
ガス中に有機化合物を添加して特定の温度で上記の触媒
に排ガスを接触させれば、10%の水分を含む排ガスで
も、広い温度領域で窒素酸化物を効果的に除去すること
ができることを発見し、本発明を完成した。
As a result of earnest research in view of the above problems, the present inventor has found that an exhaust gas purifying material or a porous inorganic oxide carrying a specific amount of a silver copper component and a gold component respectively, or a porous inorganic oxide. Using an exhaust gas purification material that supports silver copper component, gold component and components such as Pt on high quality inorganic oxide, add organic compound to the exhaust gas and contact the exhaust gas with the above catalyst at a specific temperature Then, it was discovered that nitrogen oxides can be effectively removed in a wide temperature range even with exhaust gas containing 10% of water, and the present invention has been completed.

【0011】すなわち、本発明の第一の排ガス浄化材
は、排ガス流入側に第一の触媒を有し、排ガス流出側に
第二の触媒を有して、前記第一の触媒が多孔質の無機酸
化物に活性種である銀又は銀酸化物0.2〜15重量%
(元素換算値)、銅酸化物0.01〜2重量%(元素換
算値)を担持してなり、前記第二の触媒が多孔質の無機
酸化物に活性種である金0.02〜5重量%を担持して
なり、外部から前記排ガス中に炭化水素及び/又は含酸
素有機化合物を還元剤として添加し、150〜650℃
で、前記排ガス中の窒素酸化物を還元することを特徴と
する。
That is, the first exhaust gas purifying material of the present invention has a first catalyst on the exhaust gas inflow side and a second catalyst on the exhaust gas outflow side, and the first catalyst is porous. 0.2 to 15% by weight of silver or silver oxide which is an active species in the inorganic oxide
(Elemental conversion value), copper oxide 0.01 to 2% by weight (elemental conversion value) is carried, and the second catalyst contains 0.02 to 5 gold which is an active species in a porous inorganic oxide. %, And a hydrocarbon and / or an oxygen-containing organic compound is added to the exhaust gas as a reducing agent from the outside, and the temperature is 150 to 650 ° C.
Then, the nitrogen oxide in the exhaust gas is reduced.

【0012】本発明の第二の排ガス浄化材は、第一の触
媒と第二の触媒を混合して用い、前記第一の触媒が多孔
質の無機酸化物に活性種である銀又は銀酸化物0.2〜
15重量%(元素換算値)、銅酸化物0.01〜2重量
%(元素換算値)を担持してなり、前記第二の触媒が多
孔質の無機酸化物に活性種である金0.02〜5重量%
を担持してなり、外部から前記排ガス中に炭化水素及び
/又は含酸素有機化合物を還元剤として添加し、150
〜650℃で、前記排ガス中の窒素酸化物を還元するこ
とを特徴とする。
The second exhaust gas purifying material of the present invention is a mixture of a first catalyst and a second catalyst, wherein the first catalyst is a porous inorganic oxide containing silver or silver oxide as an active species. Things 0.2 ~
15% by weight (elemental conversion value) and 0.01 to 2% by weight of copper oxide (elemental conversion value) are supported, and the second catalyst is a porous inorganic oxide containing gold, which is an active species. 02-5% by weight
A hydrocarbon and / or an oxygen-containing organic compound is added to the exhaust gas as a reducing agent from the outside.
The nitrogen oxide in the exhaust gas is reduced at ˜650 ° C.

【0013】本発明の第三の排ガス浄化材は、排ガス流
入側に第一の触媒を有し、排ガス流出側に第二の触媒を
有して、前記第一の触媒が多孔質の無機酸化物に活性種
である銀又は銀酸化物0.2〜15重量%(元素換算
値)、銅酸化物0.01〜2重量%(元素換算値)を担
持してなり、前記第二の触媒が多孔質の無機酸化物に活
性種であるPt、Pd、Ru、Rh、Irからなる群より選ばれた
少なくとも1種の元素0.02〜5重量%を担持してな
り、外部から前記排ガス中に炭化水素及び/又は含酸素
有機化合物を還元剤として添加し、150〜650℃
で、前記排ガス中の窒素酸化物を還元することを特徴と
する。
The third exhaust gas purifying material of the present invention has a first catalyst on the exhaust gas inflow side and a second catalyst on the exhaust gas outflow side, and the first catalyst is a porous inorganic oxide. The second catalyst comprises 0.2 to 15% by weight of silver or silver oxide (elemental conversion value) and 0.01 to 2% by weight of copper oxide (elemental conversion value) as active species. Is a porous inorganic oxide carrying 0.02-5% by weight of at least one element selected from the group consisting of Pt, Pd, Ru, Rh and Ir, which are active species, and the exhaust gas is externally supplied. Hydrocarbon and / or oxygen-containing organic compound is added as a reducing agent therein,
Then, the nitrogen oxide in the exhaust gas is reduced.

【0014】本発明の第四の排ガス浄化材は、第一の触
媒と第二の触媒を混合して用い、前記第一の触媒が多孔
質の無機酸化物に活性種である銀又は銀酸化物0.2〜
15重量%(元素換算値)、銅酸化物0.01〜2重量
%(元素換算値)を担持してなり、前記第二の触媒が多
孔質の無機酸化物に活性種であるPt、Pd、Ru、Rh、Irか
らなる群より選ばれた少なくとも1種の元素0.02〜
5重量%を担持してなり、外部から前記排ガス中に炭化
水素及び/又は含酸素有機化合物を還元剤として添加
し、150〜650℃で、前記排ガス中の窒素酸化物を
還元することを特徴とする。
The fourth exhaust gas purifying material of the present invention is a mixture of a first catalyst and a second catalyst, wherein the first catalyst is a porous inorganic oxide containing silver or silver oxide as an active species. Things 0.2 ~
15% by weight (elemental conversion value) and 0.01 to 2% by weight (elemental conversion value) of copper oxide are supported, and the second catalyst is Pt or Pd which is a porous inorganic oxide and is an active species. , At least one element selected from the group consisting of Ru, Rh, Ir 0.02-
5% by weight is supported, and a hydrocarbon and / or an oxygen-containing organic compound is externally added to the exhaust gas as a reducing agent to reduce nitrogen oxides in the exhaust gas at 150 to 650 ° C. And

【0015】本発明の第五の排ガス浄化材は、排ガス流
入側から流出側に順に第一、第二、第三の触媒を有し、
前記第一の触媒が多孔質の無機酸化物に活性種である銀
又は銀酸化物0.2〜15重量%(元素換算値)、銅酸
化物0.01〜2重量%(元素換算値)を担持してな
り、前記第二の触媒が多孔質の無機酸化物に活性種であ
る金0.02〜5重量%を担持してなり、前記第三の触
媒が多孔質の無機酸化物に活性種であるPt、Pd、Ru、R
h、Irからなる群より選ばれた少なくとも1種の元素
0.02〜5重量%を担持してなり、外部から前記排ガ
ス中に炭化水素及び/又は含酸素有機化合物を還元剤と
して添加し、150〜650℃で、前記排ガス中の窒素
酸化物を還元することを特徴とする排ガス浄化材。
A fifth exhaust gas purifying material of the present invention has first, second and third catalysts in order from the exhaust gas inflow side to the outflow side,
The first catalyst is a porous inorganic oxide which is an active species of silver or silver oxide 0.2 to 15% by weight (element conversion value), copper oxide 0.01 to 2% by weight (element conversion value). The second catalyst carries 0.02 to 5% by weight of gold, which is an active species, in the porous inorganic oxide, and the third catalyst becomes a porous inorganic oxide. Active species Pt, Pd, Ru, R
h, 0.02-5 wt% of at least one element selected from the group consisting of Ir is carried, and a hydrocarbon and / or an oxygen-containing organic compound is added to the exhaust gas from the outside as a reducing agent, An exhaust gas purifying material, which reduces nitrogen oxides in the exhaust gas at 150 to 650 ° C.

【0016】本発明の第六の排ガス浄化材は、第一の触
媒、第二の触媒及び第三の触媒を混合して用い、前記第
一の触媒が多孔質の無機酸化物に活性種である銀又は銀
酸化物0.2〜15重量%(元素換算値)、銅酸化物
0.01〜2重量%(元素換算値)を担持してなり、前
記第二の触媒が多孔質の無機酸化物に活性種である金
0.02〜5重量%を担持してなり、前記第三の触媒が
多孔質の無機酸化物に活性種であるPt、Pd、Ru、Rh、Ir
からなる群より選ばれた少なくとも1種の元素0.02
〜5重量%を担持してなり、外部から前記排ガス中に炭
化水素及び/又は含酸素有機化合物を還元剤として添加
し、150〜650℃で、前記排ガス中の窒素酸化物を
還元することを特徴とする排ガス浄化材。
The sixth exhaust gas purifying material of the present invention is used by mixing the first catalyst, the second catalyst and the third catalyst, and the first catalyst is a porous inorganic oxide which is an active species. 0.2 to 15% by weight of silver or silver oxide (elemental conversion value) and 0.01 to 2% by weight of copper oxide (elemental conversion value) are supported, and the second catalyst is a porous inorganic material. Pt, Pd, Ru, Rh, Ir, which is an active species supported on the porous inorganic oxide, comprises 0.02 to 5% by weight of gold as an active species on the oxide.
0.02 of at least one element selected from the group consisting of
˜5 wt% is supported, and a hydrocarbon and / or an oxygen-containing organic compound is externally added to the exhaust gas as a reducing agent to reduce nitrogen oxides in the exhaust gas at 150 to 650 ° C. Characteristic exhaust gas purification material.

【0017】さらに、窒素酸化物と、共存する未燃焼成
分に対する理論反応量より多い酸素とを含む燃焼排ガス
から窒素酸化物を除去する排ガス浄化方法は、前記排ガ
ス浄化材を排ガス導管の途中に設置し、前記浄化材の上
流側で炭化水素及び/又は含酸素有機化合物を添加した
排ガスを、150〜600℃において前記浄化材に接触
させ、もって前記排ガス中の有機化合物との反応により
前記窒素酸化物を除去することを特徴とする。
Further, in an exhaust gas purification method for removing nitrogen oxides from a combustion exhaust gas containing nitrogen oxides and oxygen in a larger amount than the theoretical reaction amount for coexisting unburned components, the exhaust gas purification material is installed in the middle of the exhaust gas conduit. Then, the exhaust gas to which the hydrocarbon and / or the oxygen-containing organic compound is added on the upstream side of the purification material is brought into contact with the purification material at 150 to 600 ° C., and the nitrogen oxidation is caused by the reaction with the organic compound in the exhaust gas. It is characterized by removing things.

【0018】以下、本発明を詳細に説明する。本発明の
排ガス浄化材は下記二つの形態をとることが可能であ
る。第一の好ましい形態は、後述の粉末状多孔質無機酸
化物に触媒活性種を担持してなる触媒を浄化材基体にコ
ートしてなる浄化材である。浄化材の基体を形成するセ
ラミックス材料としては、γ−アルミナ及びその酸化物
(γ−アルミナ−チタニア、γ−アルミナ−シリカ、γ
−アルミナ−ジルコニア等)、ジルコニア、チタニア−
ジルコニアなどの多孔質で表面積の大きい耐熱性のもの
が挙げられる。高耐熱性が要求される場合、コージェラ
イト、ムライト、アルミナ及びその複合物等を用いるの
が好ましい。また、排ガス浄化材の基体に公知の金属材
料を用いることもできる。
The present invention will be described in detail below. The exhaust gas purifying material of the present invention can take the following two forms. The first preferred form is a purifying material obtained by coating a purifying material base with a catalyst, which will be described later, carrying a catalytically active species on a powdery porous inorganic oxide. Examples of the ceramic material forming the substrate of the purification material include γ-alumina and its oxides (γ-alumina-titania, γ-alumina-silica, γ-alumina
-Alumina-zirconia, etc.), zirconia, titania-
Examples thereof include heat-resistant materials such as zirconia that are porous and have a large surface area. When high heat resistance is required, it is preferable to use cordierite, mullite, alumina and their composites. Also, a known metal material can be used for the substrate of the exhaust gas purifying material.

【0019】排ガス浄化材の基体の形状及び大きさは、
目的に応じて種々変更できる。実用的には、入口部分と
出口部分とからなる二つ又は二つ以上の部分からなるこ
とが好ましい。またその構造としては、ハニカム構造
型、フォーム型、板状、又は繊維状耐火物等の三次元網
目構造型、あるいは顆粒状、ペレット状等が挙げられ
る。
The shape and size of the substrate of the exhaust gas purifying material are
Various changes can be made according to the purpose. Practically, it is preferable to have two or more parts including an inlet part and an outlet part. Examples of the structure include a honeycomb structure type, a foam type, a plate type, a three-dimensional network structure type such as a fibrous refractory, a granular type, a pellet type and the like.

【0020】第二の好ましい形態は、ペレット状、顆粒
状、又は粉末状の多孔質無機酸化物に後述の触媒活性種
を担持してなる触媒を充填してなる浄化材であり、後述
の順序で配置する。ペレット状、顆粒状、又は粉末状の
多孔質無機酸化物に触媒活性種を担持する方法として、
含浸法などが挙げられる。
The second preferred form is a purifying material obtained by filling a catalyst in which pellet-like, granule-like, or powder-like porous inorganic oxides carry the below-mentioned catalytically active species. To place. As a method of supporting a catalytically active species on a pellet-like, granular, or powdery porous inorganic oxide,
An impregnation method and the like can be mentioned.

【0021】本発明の浄化材を構成する触媒として以下
の三つの触媒がある。 (1)第一の触媒 第一の触媒は、多孔質無機酸化物に触媒活性種である銀
成分と銅成分を担持してなり、排ガスの流入側に形成さ
れる。多孔質の無機酸化物としては、多孔質のアルミ
ナ、シリカ、チタニア、ジルコニア、及びそれらの複合
酸化物等を使用することができるが、好ましくはγ−ア
ルミナ又はアルミナ系複合酸化物を用いる。γ−アルミ
ナ又はアルミナ系複合酸化物を用いることにより、添加
した含酸素有機化合物及び/又は排ガス中の残留炭化水
素と排ガス中の窒素酸化物との反応が効率良く起こる。
There are the following three catalysts as catalysts constituting the purification material of the present invention. (1) First Catalyst The first catalyst comprises a porous inorganic oxide carrying a silver component and a copper component, which are catalytically active species, and is formed on the exhaust gas inflow side. As the porous inorganic oxide, porous alumina, silica, titania, zirconia, and their composite oxides can be used, but γ-alumina or alumina-based composite oxide is preferably used. By using γ-alumina or an alumina-based composite oxide, the reaction between the added oxygen-containing organic compound and / or the residual hydrocarbon in the exhaust gas and the nitrogen oxide in the exhaust gas occurs efficiently.

【0022】多孔質の無機酸化物の比表面積は10m2
/g以上であるのが好ましい。比表面積が10m2 /g
未満であると、排ガスと無機酸化物(及びこれに担持し
た銀、銅成分)との接触面積が小さくなり、良好な窒素
酸化物の除去が行えない。好ましい無機酸化物の比表面
積は10〜1000m2 /gとする。
The specific surface area of the porous inorganic oxide is 10 m 2
/ G or more is preferable. Specific surface area of 10 m 2 / g
If it is less than the above range, the contact area between the exhaust gas and the inorganic oxide (and the silver and copper components supported on the exhaust gas) becomes small, and the nitrogen oxide cannot be removed well. The specific surface area of the preferred inorganic oxide is 10 to 1000 m 2 / g.

【0023】上記したγ−アルミナ等の無機酸化物に活
性種として担持する銀成分の担持量は、無機酸化物10
0重量%に対して0.2〜15重量%(元素換算値)と
する。0.2重量%未満では窒素酸化物の除去率が低下
する。また、15重量%を超す量の銀を担持すると含酸
素有機化合物自身の燃焼が起きやすく、窒素酸化物の除
去率はかえって低下する。好ましい銀成分の担持量は
0.5〜10重量%である。また、上記無機酸化物に活
性種として担持する銅成分の担持量は、無機酸化物10
0重量%に対して0.01〜2重量%(元素換算値)と
する。0.01重量%未満では効果が低く、2重量%を
超すと含酸素有機化合物自身の燃焼が起きやすく、窒素
酸化物の除去率はかえって低下する。好ましい銅成分の
担持量は0.1〜1.5重量%である。なお、銀成分
は、排ガスの温度領域では金属又は酸化物の状態にあ
り、相互に容易に変換し得る。銅成分は酸化物の状態に
ある。
The amount of silver component supported as an active species on the above-mentioned inorganic oxide such as γ-alumina is such that the inorganic oxide 10
0.2 to 15% by weight (elemental conversion value) relative to 0% by weight. If it is less than 0.2% by weight, the removal rate of nitrogen oxides is lowered. On the other hand, if silver is loaded in an amount of more than 15% by weight, the oxygen-containing organic compound itself is easily burned, and the nitrogen oxide removal rate is rather lowered. A preferable amount of the silver component supported is 0.5 to 10% by weight. The amount of the copper component supported as an active species on the inorganic oxide is 10
It is 0.01 to 2% by weight (elemental conversion value) with respect to 0% by weight. If it is less than 0.01% by weight, the effect is low, and if it exceeds 2% by weight, combustion of the oxygen-containing organic compound itself easily occurs, and the nitrogen oxide removal rate is rather lowered. The supported amount of the copper component is preferably 0.1 to 1.5% by weight. The silver component is in the state of metal or oxide in the temperature range of exhaust gas and can be easily converted into each other. The copper component is in the oxide state.

【0024】γ−アルミナ等の無機酸化物に銀成分と銅
成分を担持する方法としては、公知の含浸法や、沈殿
法、混練法等を用いることができる。例えば、銀、銅の
硝酸塩、塩化物、硫酸塩、炭酸塩などの水溶液を用い
て、多孔質無機酸化物を浸漬して担持する。担持後の浄
化材の調整は、50〜150℃程度で乾燥後、100〜
600℃で段階的に昇温して焼成するのが好ましい。焼
成は、空気中又は窒素流通下、あるいは水素ガス流通
下、もしくは真空排気しながら行うのが好ましい。な
お、窒素ガスまたは水素ガス流通下で焼成した浄化材
は、最後に300〜650℃で酸化処理を行うことが好
ましい。
As a method for supporting the silver component and the copper component on the inorganic oxide such as γ-alumina, known impregnation method, precipitation method, kneading method and the like can be used. For example, an aqueous solution of silver nitrate, copper nitrate, chloride, sulfate, carbonate or the like is used to immerse and support the porous inorganic oxide. The adjustment of the purifying material after loading is performed by drying at about 50 to 150 ° C. and then 100 to
It is preferable to raise the temperature stepwise at 600 ° C. and to perform the firing. The firing is preferably performed in air or under nitrogen flow, or under hydrogen gas flow, or while evacuating. In addition, it is preferable that the purification material fired under the flow of nitrogen gas or hydrogen gas is finally subjected to an oxidation treatment at 300 to 650 ° C.

【0025】なお、上記浄化材の第一の好ましい形態で
は、浄化材基体上に設ける第一の触媒の厚さは、一般
に、基体材と、この触媒との熱膨張特性の違いから制限
される場合が多い。浄化材基体上に設ける触媒の厚さを
200μm以下とするのがよい。このような厚さとすれ
ば、圧力を大きくせず、使用中に熱衝撃等で浄化材が破
損することを防ぐことができる。浄化材基体の表面に触
媒を形成する方法は公知のウォシュコート法、ゾルーゲ
ル法、粉末法等によって行われる。
In the first preferred embodiment of the purification material, the thickness of the first catalyst provided on the purification material substrate is generally limited due to the difference in thermal expansion characteristics between the substrate material and this catalyst. In many cases. The thickness of the catalyst provided on the purification material substrate is preferably 200 μm or less. With such a thickness, it is possible to prevent the purification material from being damaged by thermal shock during use without increasing the pressure. The method of forming the catalyst on the surface of the purifying material substrate is a known washcoat method, sol-gel method, powder method or the like.

【0026】また、浄化材基体の表面上に設ける第一触
媒の量は、浄化材基体の体積に対して20〜250g/
lとするのが好ましい。触媒の量が20g/l未満では
良好なNOx の除去が行えない。一方、触媒の量が250
g/lを超えると除去特性はそれほど上がらず、圧力損
失が大きくなる。より好ましくは、浄化材基体の表面上
に設ける第一の触媒を浄化材基体の50〜200g/l
とする。
The amount of the first catalyst provided on the surface of the purification material substrate is 20 to 250 g / volume of the purification material substrate.
It is preferable that it is 1. If the amount of catalyst is less than 20 g / l, good NOx cannot be removed. On the other hand, the amount of catalyst is 250
When it exceeds g / l, the removal characteristics do not improve so much and the pressure loss increases. More preferably, the first catalyst provided on the surface of the purification material substrate is 50 to 200 g / l of the purification material substrate.
And

【0027】(2)第二の触媒 第二の触媒は、多孔質無機酸化物に金成分を担持してな
り、排ガスの流出側に形成される。多孔質無機酸化物と
しては、チタニア、酸化亜鉛、酸化マグネシウム、アル
ミナなどの多孔質で表面積の大きい耐熱性の無機酸化物
又はそれらを含む複合無機酸化物が挙げられる。好まし
くはチタニア及びチタニアを含む複合酸化物を用いる。
第一の触媒と同様に、多孔質の無機酸化物の比表面積は
10m2/g以上であることが好ましい。
(2) Second catalyst The second catalyst comprises a porous inorganic oxide carrying a gold component and is formed on the exhaust gas outflow side. Examples of the porous inorganic oxide include porous and large heat-resistant inorganic oxides such as titania, zinc oxide, magnesium oxide, and alumina, or composite inorganic oxides containing them. Preferably, titania and a composite oxide containing titania are used.
Similar to the first catalyst, the specific surface area of the porous inorganic oxide is preferably 10 m 2 / g or more.

【0028】第二の触媒で無機酸化物に担持する金成分
の合計は、上述の多孔質の無機酸化物を基準(100重量
%) として0.02〜5重量%(元素換算値)とする。
触媒活性種の量が前記基体に対して、5重量%を超す触
媒担持量とすると有機化合物の酸化燃焼のみが進み、窒
素酸化物の低減特性は低下することになる。また、0.
02重量%未満では効果が十分に現れない。好ましい金
成分の担持量は0.05〜3重量%である。
The total amount of gold components supported on the inorganic oxide by the second catalyst is 0.02 to 5% by weight (elemental conversion value) based on the above-mentioned porous inorganic oxide (100% by weight). .
When the amount of the catalytically active species exceeds 5% by weight with respect to the substrate, the amount of the catalyst supported will be such that only the oxidative combustion of the organic compound proceeds, and the nitrogen oxide reducing property deteriorates. Also, 0.
If it is less than 02% by weight, the effect is not sufficiently exhibited. The supported amount of the gold component is preferably 0.05 to 3% by weight.

【0029】また、第二の触媒の活性種として、さら
に、La、Ce等の希土類元素から選ばれた少なくとも一つ
以上の元素を2重量%以下担持することが好ましい。ま
た、Ca、Mgなどのアルカリ土類金属から選ばれた少なく
とも一つ以上の元素を2重量%以下担持することが好ま
しい。これらの元素を担持することにより、白金系の触
媒の耐熱性を向上させることができる。
As the active species of the second catalyst, it is preferable to further carry 2% by weight or less of at least one element selected from rare earth elements such as La and Ce. Further, it is preferable to support 2% by weight or less of at least one element selected from alkaline earth metals such as Ca and Mg. By supporting these elements, the heat resistance of the platinum-based catalyst can be improved.

【0030】第二の触媒における活性種の担持は、公知
の含浸法、沈澱法、ゾルーゲル法等を用いることができ
る。含浸法を用いる際、塩化金酸などの水溶液に多孔質
無機酸化物を浸漬し、70℃で乾燥後、100〜600
℃で段階的に昇温して焼成することによって行われる。
なお、担持成分は金属元素として表示しているが、通常
の浄化材の使用温度条件では担持成分は金属と酸化物の
状態で存在する。
For supporting the active species on the second catalyst, a known impregnation method, precipitation method, sol-gel method or the like can be used. When the impregnation method is used, the porous inorganic oxide is dipped in an aqueous solution of chloroauric acid and dried at 70 ° C.
It is carried out by gradually raising the temperature at ℃ and firing.
Although the supported component is shown as a metal element, the supported component exists in the state of a metal and an oxide under normal use temperature conditions of the purification material.

【0031】なお、上記浄化材の第一の好ましい形態で
は、浄化材基体上に設ける第二の触媒の厚さを100μ
m以下とするのがよい。また、浄化材基体の表面上に設
ける第二の触媒の量は、浄化材基体の体積に対して25
〜250g/lとするのが好ましい。第二の触媒を浄化
材基体にコートする方法は既述した第一の触媒の方法と
同じである。
In the first preferred embodiment of the purification material, the thickness of the second catalyst provided on the purification material substrate is 100 μm.
It is preferably m or less. Further, the amount of the second catalyst provided on the surface of the purification material substrate is 25 with respect to the volume of the purification material substrate.
It is preferably set to 250 g / l. The method of coating the purifying material substrate with the second catalyst is the same as the method of the first catalyst described above.

【0032】(3)第三の触媒 第三の触媒は、多孔質無機酸化物に触媒活性種を担持し
てなり、排ガスの流出側に形成される。多孔質無機酸化
物としては、γ−アルミナ及びその酸化物(γ−アルミ
ナ−チタニア、γ−アルミナ−シリカ、γ−アルミナ−
ジルコニア等)、ジルコニア、チタニア−ジルコニアな
どの多孔質で表面積の大きい耐熱性のセラミックスが挙
げられる。好ましくはγ−アルミナ、チタニア、ジルコ
ニア及びそれらを含む複合酸化物を用いる。第一の触媒
と同様に、多孔質の無機酸化物の比表面積は10m2
g以上であることが好ましい。
(3) Third Catalyst The third catalyst comprises a porous inorganic oxide carrying a catalytically active species and is formed on the exhaust gas outflow side. As the porous inorganic oxide, γ-alumina and its oxide (γ-alumina-titania, γ-alumina-silica, γ-alumina-
Examples thereof include heat-resistant ceramics having a large surface area such as zirconia), zirconia, and titania-zirconia. Preferably, γ-alumina, titania, zirconia and a composite oxide containing them are used. Like the first catalyst, the porous inorganic oxide has a specific surface area of 10 m 2 /
It is preferably at least g.

【0033】上記第三の触媒の活性種としては、Pt、P
d、Ru、Rh、Irからなる群より選ばれた少なくとも1種
の元素を用いる。特に、PtとRh;PdとRh;P
t、PdとRhの組み合わせは効果的である。第三の触
媒で無機酸化物に担持する活性種の合計は、上述の多孔
質の無機酸化物を基準(100重量%) として0.02〜5
重量%とする。触媒活性種の量が前記基体に対して、5
重量%を超す触媒担持量とすると含酸素有機化合物の酸
化燃焼のみが進み、窒素酸化物の低減特性は低下するこ
とになる。また、0.02重量%未満では効果が十分に
現れない。好ましい白金成分の担持量は0.05〜3重
量%である。
The active species of the third catalyst include Pt and P
At least one element selected from the group consisting of d, Ru, Rh, and Ir is used. In particular, Pt and Rh; Pd and Rh; P
The combination of t, Pd and Rh is effective. The total amount of active species supported on the inorganic oxide by the third catalyst is 0.02 to 5 based on the above-mentioned porous inorganic oxide (100% by weight).
Weight% The amount of catalytically active species is 5 with respect to the substrate.
When the amount of the catalyst supported exceeds 5% by weight, only the oxidative combustion of the oxygen-containing organic compound proceeds, and the nitrogen oxide reducing property deteriorates. Further, if it is less than 0.02% by weight, the effect is not sufficiently exhibited. The amount of the platinum component supported is preferably 0.05 to 3% by weight.

【0034】また、第三の触媒の活性種として、さらに
La、Ce等の希土類元素から選ばれた少なくとも一つ以上
の元素を10重量%以下担持することが好ましい。希土
類元素を担持することにより、白金系の触媒の耐熱性を
向上させることができる。
As the active species of the third catalyst,
It is preferable to support 10% by weight or less of at least one element selected from rare earth elements such as La and Ce. By supporting the rare earth element, the heat resistance of the platinum-based catalyst can be improved.

【0035】第三の触媒における活性種の担持は、公知
の含浸法、沈澱法、ゾルーゲル法等を用いることができ
る。含浸法を用いる際、触媒活性種元素の炭酸塩、塩酸
塩、硝酸塩、酢酸塩、水酸化物等の水溶液に多孔質無機
酸化物を浸漬し、70℃で乾燥後、100〜700℃で
段階的に昇温して焼成することによって行われる。な
お、担持成分は金属元素として表示しているが、通常の
浄化材の使用温度条件では担持成分は金属と酸化物の状
態で存在する。
For supporting the active species on the third catalyst, a known impregnation method, precipitation method, sol-gel method or the like can be used. When using the impregnation method, the porous inorganic oxide is immersed in an aqueous solution of a carbonate, a hydrochloride, a nitrate, an acetate, or a hydroxide of a catalytically active element, dried at 70 ° C., and then staged at 100 to 700 ° C. The temperature is increased and the firing is performed. Although the supported component is shown as a metal element, the supported component exists in the state of a metal and an oxide under normal use temperature conditions of the purification material.

【0036】なお、上記浄化材の第一の好ましい形態で
は、浄化材基体上に設ける第三の触媒の厚さを100μ
m以下とするのがよい。また、浄化材基体の表面上に設
ける第三の触媒の量は、浄化材基体の体積に対して25
〜250g/lとするのが好ましい。第三の触媒を浄化
材基体にコートする方法は既述した第一の触媒の方法と
同じである。
In the first preferred embodiment of the purification material, the thickness of the third catalyst provided on the purification material substrate is 100 μm.
It is preferably m or less. Further, the amount of the third catalyst provided on the surface of the purification material substrate is 25 with respect to the volume of the purification material substrate.
It is preferably set to 250 g / l. The method for coating the purifying material substrate with the third catalyst is the same as the method for the first catalyst described above.

【0037】本発明の浄化材は上記触媒を配置して用い
る。具体的には、本発明の第一の浄化材は、排ガス流入
側に銀、銅系の第一の触媒、排ガス流出側に金成分の第
二の触媒を設置してなる。本発明の第二の浄化材は、第
一の触媒と第二の触媒を混合してなる。本発明の第三の
浄化材は、排ガス流入側に銀、銅系の第一の触媒、排ガ
ス流出側に白金系の第三の触媒を設置してなる。本発明
の第四の浄化材は、第一の触媒と第三の触媒を混合して
なる。本発明の第五の浄化材は、排ガス流入側から流出
側に順に第一の触媒、第二の触媒、第三の触媒を設置し
てなる。本発明の第六の浄化材は、第一の触媒、第二の
触媒、及び第三の触媒を混合してなる。
In the purifying material of the present invention, the above catalyst is arranged and used. Specifically, the first purifying material of the present invention has a first catalyst of silver or copper based on the exhaust gas inflow side and a second catalyst of gold component on the exhaust gas outflow side. The second purifying material of the present invention is a mixture of the first catalyst and the second catalyst. The third purification material of the present invention comprises a silver- and copper-based first catalyst on the exhaust gas inflow side and a platinum-based third catalyst on the exhaust gas outflow side. The fourth purifying material of the present invention is a mixture of the first catalyst and the third catalyst. The fifth purification material of the present invention comprises a first catalyst, a second catalyst, and a third catalyst, which are installed in this order from the exhaust gas inflow side to the outflow side. The sixth purifying material of the present invention is a mixture of the first catalyst, the second catalyst, and the third catalyst.

【0038】本発明においては、第一の触媒と、第二の
触媒との重量比は、5:1〜1:5とするのが好まし
い。比率が1:5未満である(第一の触媒が少ない)
と、250〜600℃の広い温度範囲で全体的に窒素酸
化物の浄化率が低下する。一方、比率が5:1を超える
(第一の触媒が多い)と、400℃以下における窒素酸
化物の浄化能が大きくならない。すなわち、比較的低温
での還元剤と窒素酸化物との反応が十分に進行しない。
より好ましい第一触媒と第二触媒の重量比は4:1〜
1:4である。
In the present invention, the weight ratio of the first catalyst to the second catalyst is preferably 5: 1 to 1: 5. The ratio is less than 1: 5 (less first catalyst)
Then, the purification rate of nitrogen oxides is generally lowered in a wide temperature range of 250 to 600 ° C. On the other hand, when the ratio exceeds 5: 1 (the amount of the first catalyst is large), the purifying ability of nitrogen oxides at 400 ° C or lower does not increase. That is, the reaction between the reducing agent and the nitrogen oxide does not proceed sufficiently at a relatively low temperature.
More preferable weight ratio of the first catalyst to the second catalyst is from 4: 1 to
It is 1: 4.

【0039】また、第一の触媒と、第三の触媒との重量
比は、5:1〜1:5とするのが好ましい。比率が1:
5未満である(第一の触媒が少ない)と、窒素酸化物の
浄化率が低下する。一方、比率が5:1を超える(第一
の触媒が多い)と、400℃以下における窒素酸化物の
浄化能が大きくならない。より好ましい第一触媒と第三
触媒の重量比は4:1〜1:4である。
The weight ratio of the first catalyst to the third catalyst is preferably 5: 1 to 1: 5. Ratio is 1:
When it is less than 5 (the amount of the first catalyst is small), the purification rate of nitrogen oxides decreases. On the other hand, when the ratio exceeds 5: 1 (the amount of the first catalyst is large), the purifying ability of nitrogen oxides at 400 ° C or lower does not increase. A more preferable weight ratio of the first catalyst to the third catalyst is 4: 1 to 1: 4.

【0040】さらに、第二の触媒と、第三の触媒との重
量比は、5:1〜1:5とするのが好ましい。比率が
1:5未満である(第二の触媒が少ない)と、窒素酸化
物の浄化率が低下する。一方、比率が5:1を超える
(第二の触媒が多い)と、400℃以下における窒素酸
化物の浄化能が大きくならない。より好ましい第二触媒
と第三触媒の重量比は4:1〜1:4である。
Further, the weight ratio of the second catalyst to the third catalyst is preferably 5: 1 to 1: 5. If the ratio is less than 1: 5 (the amount of the second catalyst is small), the purification rate of nitrogen oxides decreases. On the other hand, when the ratio exceeds 5: 1 (the amount of the second catalyst is large), the purifying ability of nitrogen oxides at 400 ° C or lower does not increase. A more preferable weight ratio of the second catalyst to the third catalyst is 4: 1 to 1: 4.

【0041】上述した構成の浄化材を用いれば、150
〜650℃の広い温度領域において、水分を10%程度
を含む排ガスでも、良好な窒素酸化物の除去を行うこと
ができる。
If the purifying material having the above structure is used,
In a wide temperature range of up to 650 ° C., good nitrogen oxides can be removed even with exhaust gas containing about 10% of water.

【0042】次に、本発明の方法について説明する。ま
ず、上記本発明の排ガス浄化材を排ガス導管の途中に設
置する。
Next, the method of the present invention will be described. First, the exhaust gas purifying material of the present invention is installed in the middle of an exhaust gas conduit.

【0043】排ガス中には、残留炭化水素としてエチレ
ン、プロピレン等がある程度は含まれるが、一般に排ガ
ス中のNOx を還元するのに十分な量ではないので、外部
から炭化水素及び/又は含酸素有機化合物からなる還元
剤を排ガス中に導入する。還元剤の導入位置は、浄化材
を設置した位置より上流側である。
The exhaust gas contains ethylene, propylene and the like as residual hydrocarbons to some extent, but since the amount is generally not sufficient to reduce NOx in the exhaust gas, hydrocarbons and / or oxygen-containing organic substances are externally supplied. A reducing agent consisting of a compound is introduced into the exhaust gas. The introduction position of the reducing agent is upstream of the position where the purification material is installed.

【0044】外部から導入する炭化水素としては、標準
状態でガス状又は液体状のアルカン、アルケン及び/又
はアルキンを用いることができる。特にアルカン又はア
ルケンの場合では炭素数3以上が好ましい。標準状態で
液体状の炭化水素としては、具体的に、アセチレン、軽
油、セタン、ヘプタン、灯油等の炭化水素が挙げられ
る。含酸素有機化合物として、エタノール等の炭素数2
以上のアルコール類を用いることができる。
As the hydrocarbon introduced from the outside, gaseous or liquid alkane, alkene and / or alkyne in a standard state can be used. Particularly in the case of alkane or alkene, the number of carbon atoms is preferably 3 or more. Specific examples of the liquid hydrocarbon in the standard state include hydrocarbons such as acetylene, light oil, cetane, heptane, and kerosene. As an oxygen-containing organic compound, it has 2 carbon atoms such as ethanol.
The above alcohols can be used.

【0045】外部から導入する含酸素有機化合物の量
は、重量比(添加する還元剤の重量/排ガス中の窒素酸
化物の重量)が5以下となるようにするのが好ましい。
この重量比が5を超えると、燃費悪化につながる。
The amount of the oxygen-containing organic compound introduced from the outside is preferably such that the weight ratio (weight of reducing agent added / weight of nitrogen oxide in exhaust gas) is 5 or less.
If this weight ratio exceeds 5, it leads to deterioration of fuel efficiency.

【0046】本発明では、炭化水素、含酸素有機化合物
等による窒素酸化物の還元除去を効率的に進行させるた
めに排ガスと浄化材中の各触媒との接触時間は0.00
5g・秒/ml以上とする。触媒との接触時間が0.00
5g・秒/ml未満であると、窒素酸化物の還元反応が十
分に起こらず、窒素酸化物の除去率が低下する。好まし
くは接触時間が0.006g・秒/ml以上とする。
In the present invention, the contact time between the exhaust gas and each catalyst in the purifying material is 0.00 in order to efficiently reduce and remove nitrogen oxides by hydrocarbons, oxygen-containing organic compounds and the like.
5g · sec / ml or more. Contact time with catalyst 0.00
If it is less than 5 g · sec / ml, the reduction reaction of nitrogen oxides does not sufficiently occur, and the removal rate of nitrogen oxides decreases. The contact time is preferably 0.006 g · sec / ml or more.

【0047】また、本発明では、含酸素有機化合物と窒
素酸化物とが反応する部位である浄化材設置部位におけ
る排ガスの温度を150〜650℃に保つ。排ガスの温
度が150℃未満であると還元剤と窒素酸化物との反応
が進行せず、良好な窒素酸化物の除去を行うことができ
ない。一方、650℃を超す温度とすると含酸素有機化
合物自身の燃焼が始まり、窒素酸化物の還元除去が行え
ない。好ましい排ガス温度は、300〜600℃であ
る。
Further, in the present invention, the temperature of the exhaust gas at the purification material installation site, which is the site where the oxygen-containing organic compound reacts with the nitrogen oxides, is maintained at 150 to 650 ° C. If the temperature of the exhaust gas is less than 150 ° C., the reaction between the reducing agent and the nitrogen oxide does not proceed, and the nitrogen oxide cannot be removed satisfactorily. On the other hand, if the temperature exceeds 650 ° C., the oxygen-containing organic compound itself starts to burn, and the nitrogen oxide cannot be reduced and removed. A preferable exhaust gas temperature is 300 to 600 ° C.

【0048】[0048]

【実施例】本発明を以下の具体的実施例によりさらに詳
細に説明する。実施例1 市販のペレット状γ−アルミナ(直径1.5mm、長さ約
6mm、比表面積200m2 /g)5gに、硝酸銀、硝酸
銅水溶液を用いて銀を2重量%、銅を0.5重量%担持
し、乾燥後、空気中で600℃まで段階的に焼成し、触
媒1を調製した。同様に、ペレット状チタニア(直径
1.5mm、長さ約6mm、比表面積20m2/g)5gに
塩化金酸水溶液を用いて、金を1重量%担持し、乾燥
後、空気中で700℃まで焼成し、触媒2を調製した。
The present invention will be described in more detail by the following specific examples. Example 1 To 5 g of commercially available pelletized γ-alumina (diameter: 1.5 mm, length: about 6 mm, specific surface area: 200 m 2 / g), silver nitrate and copper nitrate aqueous solution were used, and 2% by weight of silver and 0.5 of copper were used. The catalyst 1 was prepared by supporting the catalyst in a weight percentage, drying, and then calcining the mixture in air in steps up to 600 ° C. Similarly, 5 g of pelletized titania (diameter 1.5 mm, length about 6 mm, specific surface area 20 m 2 / g) was loaded with 1% by weight of gold using an aqueous solution of chloroauric acid, dried, and then dried at 700 ° C. in air. And was calcined to prepare catalyst 2.

【0049】銀系触媒3.7gと金系触媒1.8gを混
合した浄化材を反応管内にセットした。次に、表1に示
す組成のガス(一酸化窒素、一酸化炭素、酸素、プロピ
レン、及び窒素)を毎分4.4リットル(標準状態)の
流量で流して(全体の見かけ空間速度約20,000h
-1、銀系触媒と金触媒の接触時間はそれぞれ0.05、
0.025秒・g/ml)、反応管内の排ガス温度を20
0〜700℃の範囲に保ち、プロピレンと窒素酸化物と
を反応させた。
A purification material in which 3.7 g of the silver-based catalyst and 1.8 g of the gold-based catalyst were mixed was set in the reaction tube. Next, a gas having a composition shown in Table 1 (nitrogen monoxide, carbon monoxide, oxygen, propylene, and nitrogen) was flowed at a flow rate of 4.4 liters per minute (standard state) (total apparent space velocity of about 20). 1,000 h
-1 , the contact time of silver catalyst and gold catalyst is 0.05,
0.025 seconds ・ g / ml), the exhaust gas temperature in the reaction tube is set to 20
The temperature was kept in the range of 0 to 700 ° C., and propylene was reacted with nitrogen oxide.

【0050】反応管通過後のガスの窒素酸化物の濃度を
化学発光式窒素酸化物分析計により測定し、窒素酸化物
の除去率を求めた。結果を図1に示す。
The nitrogen oxide concentration of the gas after passing through the reaction tube was measured by a chemiluminescence type nitrogen oxide analyzer to determine the nitrogen oxide removal rate. The results are shown in Fig. 1.

【0051】表1成分 濃度 一酸化窒素 800 ppm 一酸化炭素 100 ppm 酸素 10 容量% 水分 10 容量% プロピレン 1714 ppm 窒素 残部Table 1 Component Concentration Nitric oxide 800 ppm Carbon monoxide 100 ppm Oxygen 10% by volume Moisture 10% by volume Propylene 1714 ppm Nitrogen balance

【0052】実施例2 硝酸銀、硝酸銅水溶液を用いて粉末状γ−アルミナ(比
表面積200m2 /g)に銀2重量%、銅0.5重量%
が担持されている触媒作成し、この触媒約1.0gを市
販のコージェライト製ハニカム状成形体(直径30mm、
長さ12.6mm、400セル/平方インチ)に、コート
し、乾燥後、600℃まで段階的に焼成し、浄化材を調
製した。また、同様のハニカム状成形体(長さ6mm)に
塩化金酸溶液を用いて、粉末状チタニア(比表面積50
2 /g)に金が1重量%担持されている触媒0.4g
をコートし、乾燥後、700℃まで焼成し、浄化材を調
製した。排ガスの流入側に銀、銅系浄化材、流出側に金
浄化材になるように、反応管内にセットした。表1に示
す成分のガスを用い、実施例1と同様の条件でこの浄化
材を評価した(全体の見かけ空間速度20,000
-1)。実験結果を図1に示す。
Example 2 2% by weight of silver and 0.5% by weight of copper were added to powdery γ-alumina (specific surface area 200 m 2 / g) using an aqueous solution of silver nitrate and copper nitrate.
Was prepared, and about 1.0 g of this catalyst was put on a commercially available cordierite honeycomb-shaped compact (diameter 30 mm,
A length of 12.6 mm, 400 cells / in 2) was coated, dried, and then fired stepwise to 600 ° C. to prepare a purification material. In addition, a powdered titania (specific surface area 50) was prepared by using a chloroauric acid solution in the same honeycomb shaped body (length 6 mm).
0.4 g of catalyst in which 1% by weight of gold is supported on m 2 / g)
Was coated, dried, and fired to 700 ° C. to prepare a purification material. It was set in the reaction tube so that the inflow side of the exhaust gas was a silver-based purification material and the outflow side was a gold purification material. This purification material was evaluated under the same conditions as in Example 1 using the gases having the components shown in Table 1 (total apparent space velocity 20,000).
h -1 ). The experimental results are shown in FIG.

【0053】実施例3 実施例2で作成した浄化材を用いて、表1に示すガス組
成の内プロピレンに換えて軽油(添加量は窒素酸化物の
質量の3倍)を用いて、実施例2と同様な方法で評価し
た。実験結果を図1に示す。
Example 3 Using the purification material prepared in Example 2, light oil (addition amount was 3 times the mass of nitrogen oxide) was used instead of propylene in the gas composition shown in Table 1. Evaluation was performed in the same manner as in 2. The experimental results are shown in FIG.

【0054】比較例1 実施例1と同様な方法で、γ−アルミナペレット10g
に銀を5重量%担持した浄化材を作成した。この浄化材
3.6gを反応管にセットし、表1に示す組成のガスで
評価した。実験結果を図1に示す。
Comparative Example 1 In the same manner as in Example 1, 10 g of γ-alumina pellets
A purification material was prepared by supporting 5% by weight of silver. 3.6 g of this purification material was set in a reaction tube, and the gas having the composition shown in Table 1 was evaluated. The experimental results are shown in FIG.

【0055】以上からわかるように、実施例1〜3にお
いては、広い排ガス温度範囲で窒素酸化物の良好な除去
がみられた。一方、比較例1においては、窒素酸化物除
去の温度範囲が狭かった。
As can be seen from the above, in Examples 1 to 3, good removal of nitrogen oxides was observed in a wide exhaust gas temperature range. On the other hand, in Comparative Example 1, the temperature range for removing nitrogen oxides was narrow.

【0056】実施例4 市販のペレット状γ−アルミナ(直径1.5mm、長さ約
6mm、比表面積200m2 /g)5gに、硝酸銀、硝酸
銅水溶液を用いて銀を2重量%、銅を0.5重量%担持
し、乾燥後、空気中で600℃まで段階的に焼成し、触
媒1を調製した。同様に、ペレット状γ−アルミナ(直
径1.5mm、長さ約6mm、比表面積200m2 /g)5
gに塩化白金酸水溶液を用いて、白金を2重量%担持
し、乾燥後、空気中で700℃まで焼成し、触媒2を調
製した。
Example 4 To 5 g of commercially available pelletized γ-alumina (diameter: 1.5 mm, length: about 6 mm, specific surface area: 200 m 2 / g), silver nitrate, copper nitrate aqueous solution was used to add 2% by weight of silver and copper. The catalyst 1 was prepared by supporting 0.5% by weight, drying and then calcining stepwise in air to 600 ° C. Similarly, pelletized γ-alumina (diameter 1.5 mm, length about 6 mm, specific surface area 200 m 2 / g) 5
A platinum chloroplatinic acid aqueous solution was used for g to support 2% by weight of platinum, dried and then calcined in air to 700 ° C. to prepare a catalyst 2.

【0057】銀系触媒3.7gと白金系触媒1.8gを
混合した浄化材を反応管内にセットした。次に、表1に
示す組成のガス(一酸化窒素、一酸化炭素、酸素、プロ
ピレン、及び窒素)を毎分4.4リットル(標準状態)
の流量で流して(全体の見かけ空間速度約20,000
-1、銀、銅系触媒と金触媒の接触時間はそれぞれ0.
05、0.025秒・g/ml)、反応管内の排ガス温度
を200〜700℃の範囲に保ち、プロピレンと窒素酸
化物とを反応させた。
A purification material in which 3.7 g of the silver-based catalyst and 1.8 g of the platinum-based catalyst were mixed was set in the reaction tube. Next, 4.4 liters / min of gas (nitrogen monoxide, carbon monoxide, oxygen, propylene, and nitrogen) having the composition shown in Table 1 (standard state)
At a flow rate of (total apparent space velocity of about 20,000
h -1, silver, respectively copper-based catalyst and gold catalyst contact time 0.
(05, 0.025 sec · g / ml), the temperature of the exhaust gas in the reaction tube was kept in the range of 200 to 700 ° C., and propylene and nitrogen oxide were reacted.

【0058】反応管通過後のガスの窒素酸化物の濃度を
化学発光式窒素酸化物分析計により測定し、窒素酸化物
の除去率を求めた。結果を図2に示す。
The nitrogen oxide concentration of the gas after passing through the reaction tube was measured by a chemiluminescence type nitrogen oxide analyzer to determine the nitrogen oxide removal rate. The results are shown in Figure 2.

【0059】実施例5 硝酸銀、硝酸銅水溶液を用いて粉末状γ−アルミナ(比
表面積200m2 /g)に銀2重量%、銅0.5重量%
が担持されている触媒作成し、この触媒約1.0gを市
販のコージェライト製ハニカム状成形体(直径30mm、
長さ12.6mm、400セル/平方インチ)に、コート
し、乾燥後、600℃まで段階的に焼成し、浄化材を調
製した。また、同様のハニカム状成形体(長さ6mm)に
塩化白金酸溶液を用いて、粉末状アルミナ(比表面積2
00m2 /g)に白金が1重量%担持されている触媒
0.4gをコートし、乾燥後、700℃まで焼成し、浄
化材を調製した。排ガスの流入側に銀、銅系浄化材、流
出側に白金浄化材になるように、反応管内にセットし
た。表1に示す成分のガスを用い、実施例4と同様の条
件でこの浄化材を評価した(全体の見かけ空間速度2
0,000h-1)。実験結果を図2に示す。
Example 5 2% by weight of silver and 0.5% by weight of copper were added to powdery γ-alumina (specific surface area 200 m 2 / g) using an aqueous solution of silver nitrate and copper nitrate.
Was prepared, and about 1.0 g of this catalyst was put on a commercially available cordierite honeycomb-shaped compact (diameter 30 mm,
A length of 12.6 mm, 400 cells / in 2) was coated, dried, and then fired stepwise to 600 ° C. to prepare a purification material. In addition, a chloroplatinic acid solution was used for the same honeycomb-shaped compact (length 6 mm), and powdered alumina (specific surface area 2
0.4 m of a catalyst in which 1% by weight of platinum was supported was coated on 100 m 2 / g), dried, and calcined to 700 ° C. to prepare a purification material. It was set in the reaction tube so that the inflow side of the exhaust gas was a silver-based or copper-based cleaning material and the outflow side was a platinum-based cleaning material. This purification material was evaluated under the same conditions as in Example 4 using the gases having the components shown in Table 1 (total apparent space velocity 2
10,000 h -1 ). The experimental results are shown in FIG.

【0060】実施例6 実施例5で作成した浄化材を用いて、表1に示すガス組
成の内プロピレンに換えて軽油(添加量は窒素酸化物の
質量の3倍)を用いて、実施例5と同様な方法で評価し
た。実験結果を図2に示す。
Example 6 Using the purification material prepared in Example 5, light oil (addition amount is 3 times the mass of nitrogen oxide) was used in place of propylene in the gas composition shown in Table 1. Evaluation was made in the same manner as in 5. The experimental results are shown in FIG.

【0061】比較のため、比較例1も合わせて図2に示
した。図2からわかるように、実施例4〜6において
は、広い排ガス温度範囲で窒素酸化物の良好な除去がみ
られた。一方、比較例1においては、窒素酸化物除去の
温度範囲が狭かった。
For comparison, Comparative Example 1 is also shown in FIG. As can be seen from FIG. 2, in Examples 4 to 6, good removal of nitrogen oxides was observed in a wide exhaust gas temperature range. On the other hand, in Comparative Example 1, the temperature range for removing nitrogen oxides was narrow.

【0062】実施例7 市販のペレット状γ−アルミナ(直径1.5mm 、長さ約6
mm、比表面積200m2 /g)5gに、硝酸銀、硝酸銅
水溶液を用いて銀を2重量%、銅を0.5重量%担持
し、乾燥後、600℃まで段階的に焼成し、第一の触媒
を調製した。また、ペレット状チタニア(直径1.5mm 、
長さ約6 mm、比表面積20m2 /g)5gに塩化金酸水
溶液を用いて、金を1重量%担持し、乾燥後、空気中で
700℃まで焼成し、第二の触媒を調製した。さらに、
第一の触媒と同様のペレット状γ−アルミナ(直径1.5m
m 、長さ約6 mm、比表面積200m2 /g)5gに塩化
白金酸水溶液を用いて、Ptを2重量%担持し、乾燥後、
空気中で700℃まで焼成し、第三の触媒を調製した。
Example 7 Commercially available pelletized γ-alumina (diameter 1.5 mm, length about 6)
mm, specific surface area 200 m 2 / g), 5 g of silver nitrate and copper nitrate aqueous solution were used to carry 2 wt% of silver and 0.5 wt% of copper, and after drying, calcined stepwise to 600 ° C. Was prepared. Also, pelletized titania (diameter 1.5 mm,
A second catalyst was prepared by supporting 1% by weight of gold with an aqueous solution of chloroauric acid on 5 g of a length of about 6 mm and a specific surface area of 20 m 2 / g, drying and firing to 700 ° C. in air. . further,
Similar to the first catalyst, pelletized γ-alumina (diameter 1.5m
m, length of about 6 mm, specific surface area of 200 m 2 / g) 5 g of Pt was loaded on 5 g of chloroplatinic acid aqueous solution, and after drying,
A third catalyst was prepared by calcining in air to 700 ° C.

【0063】浄化材を、排ガスの流入側から順に、銀、
銅系第一の触媒3.7g、金系第二の触媒1.8g、Pt
系第三の触媒1.8gを混合して浄化材とし、反応管内
にセットした。次に、表1に示す組成のガス(一酸化炭
素、一酸化窒素、酸素、プロピレン、及び窒素)を毎分
4.4リットル(標準状態)の流量で流して(全体の見
かけ空間速度約15,000h-1、銀、銅系触媒、金系
触媒とPt系触媒の接触時間はそれぞれ0.05、0.0
25、0.025秒・g/ml)、反応管内の排ガス温度
を200〜700℃の範囲に保ち、プロピレンと窒素酸
化物とを反応させた。
The purifying materials were silver, in order from the inflow side of the exhaust gas,
Copper-based first catalyst 3.7g, gold-based second catalyst 1.8g, Pt
1.8 g of the third catalyst of the system was mixed as a purification material and set in the reaction tube. Next, a gas having the composition shown in Table 1 (carbon monoxide, nitric oxide, oxygen, propylene, and nitrogen) was flowed at a flow rate of 4.4 liters per minute (standard state) (total apparent space velocity of about 15 2,000h -1 , the contact time of silver, copper catalyst, gold catalyst and Pt catalyst is 0.05 and 0.0, respectively.
25, 0.025 sec.g / ml), the temperature of the exhaust gas in the reaction tube was kept in the range of 200 to 700 ° C., and propylene and nitrogen oxide were reacted.

【0064】反応管通過後のガスの窒素酸化物の濃度を
化学発光式窒素酸化物分析計により測定し、窒素酸化物
の除去率を求めた。結果を図3に示す。
The nitrogen oxide concentration of the gas after passing through the reaction tube was measured by a chemiluminescence type nitrogen oxide analyzer to determine the nitrogen oxide removal rate. The results are shown in Fig. 3.

【0065】実施例8 市販のコージェライト製ハニカム状成形体(直径30m
m、長さ約12.6mm、400セル/平方インチ)に、
硝酸銀、硝酸銅水溶液を用いて粉末状γ−アルミナ(比
表面積200m2 /g)に銀2重量%、銅0.5重量%
が担持されている触媒約1gをコートし、乾燥後、60
0℃まで段階的に焼成し、浄化材を調製した。また、同
様のハニカム状成形体(長さ6mm)に、粉末状γ−アル
ミナにPtが1重量%担持されている触媒0.4gをコー
トし、乾燥後、700℃まで焼成し、浄化材を調製し
た。さらに、同様のハニカム状成形体(長さ6mm)に塩
化金酸水溶液を用いて、粉末状チタニア(比表面積50
2 /g)に金が1重量%担持されている触媒0.4g
をコートし、乾燥後、700℃まで焼成し、浄化材を調
製した。排ガスの流入側から、銀、銅系浄化材、金系浄
化材、Pt系浄化材の順に組み合わせて、反応管内にセッ
トし、表1と同組成のガスで実施例7と同じ方法で評価
した(全体の見かけ空間速度約15,000h-1)。実
験結果を図3に示す。
Example 8 Commercially available cordierite honeycomb-shaped molded body (diameter 30 m
m, length about 12.6 mm, 400 cells / square inch),
2% by weight of silver and 0.5% by weight of copper in powdery γ-alumina (specific surface area 200 m 2 / g) using an aqueous solution of silver nitrate and copper nitrate
After coating about 1 g of the catalyst carrying
A purification material was prepared by firing in stages to 0 ° C. In addition, a similar honeycomb shaped body (length 6 mm) was coated with 0.4 g of a catalyst in which 1 wt% of Pt was supported on powdery γ-alumina, dried, and fired to 700 ° C to obtain a purification material. Prepared. Furthermore, a powdery titania (specific surface area 50
0.4 g of catalyst in which 1% by weight of gold is supported on m 2 / g)
Was coated, dried, and fired to 700 ° C. to prepare a purification material. From the inflow side of the exhaust gas, silver, a copper-based purification material, a gold-based purification material, and a Pt-based purification material were combined in this order, set in a reaction tube, and evaluated with the same method as in Example 7 using a gas having the same composition as in Table 1. (Overall apparent space velocity of about 15,000 h -1 ). The experimental results are shown in FIG.

【0066】実施例9 実施例8で作成した浄化材を用いて、表1に示すガス組
成の内プロピレンに換えて軽油(添加量は窒素酸化物の
質量の3倍)を用いて、実施例8と同様な方法で評価し
た。実験結果を図3に示す。
Example 9 Using the purification material prepared in Example 8, light oil (addition amount was 3 times the mass of nitrogen oxide) was used instead of propylene in the gas composition shown in Table 1. Evaluation was made in the same manner as in 8. The experimental results are shown in FIG.

【0067】比較のため、比較例1も合わせて図3に示
した。図3からわかるように、実施例7〜9において
は、広い排ガス温度範囲で窒素酸化物の良好な除去がみ
られた。一方、比較例1においては、窒素酸化物除去の
温度範囲が狭かった。
For comparison, Comparative Example 1 is also shown in FIG. As can be seen from FIG. 3, in Examples 7 to 9, good removal of nitrogen oxides was observed in a wide exhaust gas temperature range. On the other hand, in Comparative Example 1, the temperature range for removing nitrogen oxides was narrow.

【0068】[0068]

【発明の効果】以上詳述したように、本発明の排ガス浄
化材を用いれば、広い温度領域において過剰の酸素を含
む排ガス中の窒素酸化物を効率良く除去することができ
る。本発明の排ガス浄化材及び浄化方法は、各種燃焼
機、自動車等の排ガス浄化に広く利用することができ
る。
As described above in detail, by using the exhaust gas purifying material of the present invention, nitrogen oxides in exhaust gas containing excess oxygen can be efficiently removed in a wide temperature range. INDUSTRIAL APPLICABILITY The exhaust gas purifying material and the purifying method of the present invention can be widely used for purifying exhaust gas of various combustors, automobiles and the like.

【図面の簡単な説明】[Brief description of drawings]

【図1】実施例1〜3及び比較例1における排ガス温度
と排ガス中の窒素酸化物の除去率の関係を示すグラフで
ある。
FIG. 1 is a graph showing the relationship between the exhaust gas temperature and the removal rate of nitrogen oxides in the exhaust gas in Examples 1 to 3 and Comparative Example 1.

【図2】実施例4〜6及び比較例1における排ガス温度
と排ガス中の窒素酸化物の除去率の関係を示すグラフで
ある。
FIG. 2 is a graph showing the relationship between the exhaust gas temperature and the removal rate of nitrogen oxides in the exhaust gas in Examples 4 to 6 and Comparative Example 1.

【図3】実施例4〜6及び比較例1における排ガス温度
と排ガス中の窒素酸化物の除去率の関係を示すグラフで
ある。
FIG. 3 is a graph showing the relationship between the exhaust gas temperature and the removal rate of nitrogen oxides in the exhaust gas in Examples 4 to 6 and Comparative Example 1.

───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 FI 技術表示箇所 B01J 23/52 ZAB A 8017−4G 35/02 ZAB P 8017−4G B01D 53/36 102 H ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification code Internal reference number FI Technical display location B01J 23/52 ZAB A 8017-4G 35/02 ZAB P 8017-4G B01D 53/36 102 H

Claims (12)

【特許請求の範囲】[Claims] 【請求項1】 窒素酸化物と、共存する未燃焼成分に対
する理論反応量より多い酸素とを含む燃焼排ガスに外部
から炭化水素及び/又は含酸素有機化合物を還元剤とし
て添加して窒素酸化物を還元除去する排ガス浄化材にお
いて、排ガス流入側に第一の触媒を有し、排ガス流出側
に第二の触媒を有し、前記第一の触媒が多孔質の無機酸
化物に活性種である銀又は銀酸化物0.2〜15重量%
(元素換算値)、銅酸化物0.01〜2重量%(元素換
算値)を担持してなり、前記第二の触媒が多孔質の無機
酸化物に活性種である金0.02〜5重量%を担持して
いることを特徴とする排ガス浄化材。
1. A nitrogen oxide is obtained by externally adding a hydrocarbon and / or an oxygen-containing organic compound as a reducing agent to a combustion exhaust gas containing nitrogen oxide and oxygen in a larger amount than the theoretical reaction amount for coexisting unburned components. In an exhaust gas purifying material for reduction and removal, a first catalyst is provided on the exhaust gas inflow side and a second catalyst is provided on the exhaust gas outflow side, and the first catalyst is silver that is an active species in a porous inorganic oxide. Or 0.2 to 15% by weight of silver oxide
(Elemental conversion value), copper oxide 0.01 to 2% by weight (elemental conversion value) is carried, and the second catalyst contains 0.02 to 5 gold which is an active species in a porous inorganic oxide. An exhaust gas purifying material, which is characterized by supporting weight%.
【請求項2】 窒素酸化物と、共存する未燃焼成分に対
する理論反応量より多い酸素とを含む燃焼排ガスに外部
から炭化水素及び/又は含酸素有機化合物を還元剤とし
て添加して窒素酸化物を還元除去する排ガス浄化材にお
いて、第一の触媒と第二の触媒を混合して用い、前記第
一の触媒が多孔質の無機酸化物に活性種である銀又は銀
酸化物0.2〜15重量%(元素換算値)、銅酸化物
0.01〜2重量%(元素換算値)を担持してなり、前
記第二の触媒が多孔質の無機酸化物に活性種である金
0.02〜5重量%を担持していることを特徴とする排
ガス浄化材。
2. A nitrogen oxide is obtained by externally adding a hydrocarbon and / or an oxygen-containing organic compound as a reducing agent to a combustion exhaust gas containing nitrogen oxide and oxygen in a larger amount than the theoretical reaction amount for coexisting unburned components. In an exhaust gas purifying material for reduction and removal, a first catalyst and a second catalyst are mixed and used, and the first catalyst is silver or silver oxide 0.2 to 15 which is an active species of a porous inorganic oxide. % Of gold (elemental conversion value) and 0.01 to 2% by weight of copper oxide (elemental conversion value), and the second catalyst is a porous inorganic oxide containing 0.02% of gold as an active species. An exhaust gas purifying material, characterized in that the exhaust gas purifying material carries 5% to 5% by weight.
【請求項3】 請求項1又は2に記載の排ガス浄化材に
おいて、前記多孔質無機酸化物が、第一の触媒ではγ−
アルミナ又はアルミナ系複合酸化物で、第二の触媒では
アルミナ、チタニア、酸化亜鉛、酸化マグネシウムのい
ずれか又はその内の二つ以上からなる複合酸化物である
ことを特徴とする排ガス浄化材。
3. The exhaust gas purifying material according to claim 1, wherein the porous inorganic oxide is γ-in the first catalyst.
An exhaust gas purifying material, characterized in that it is an alumina or an alumina-based composite oxide, and the second catalyst is any one of alumina, titania, zinc oxide, magnesium oxide, or a composite oxide composed of two or more thereof.
【請求項4】 窒素酸化物と、共存する未燃焼成分に対
する理論反応量より多い酸素とを含む燃焼排ガスに外部
から炭化水素及び/又は含酸素有機化合物を還元剤とし
て添加して窒素酸化物を還元除去する排ガス浄化材にお
いて、排ガス流入側に第一の触媒を有し、排ガス流出側
に第二の触媒を有し、前記第一の触媒が多孔質の無機酸
化物に活性種である銀又は銀酸化物0.2〜15重量%
(元素換算値)、銅酸化物0.01〜2重量%(元素換
算値)を担持してなり、前記第二の触媒が多孔質の無機
酸化物に活性種であるPt、Pd、Ru、Rh、Irからなる群よ
り選ばれた少なくとも1種の元素0.02〜5重量%を
担持していることを特徴とする排ガス浄化材。
4. A nitrogen oxide is obtained by externally adding a hydrocarbon and / or an oxygen-containing organic compound as a reducing agent to a combustion exhaust gas containing nitrogen oxide and oxygen in a larger amount than the theoretical reaction amount for coexisting unburned components. In an exhaust gas purifying material for reduction and removal, a first catalyst is provided on the exhaust gas inflow side and a second catalyst is provided on the exhaust gas outflow side, and the first catalyst is silver that is an active species in a porous inorganic oxide. Or 0.2 to 15% by weight of silver oxide
(Elemental conversion value), 0.01 to 2% by weight of copper oxide (elemental conversion value) is carried, and the second catalyst is Pt, Pd, Ru, which is an active species in a porous inorganic oxide, An exhaust gas purifying material, which carries 0.02 to 5% by weight of at least one element selected from the group consisting of Rh and Ir.
【請求項5】 窒素酸化物と、共存する未燃焼成分に対
する理論反応量より多い酸素とを含む燃焼排ガスに外部
から炭化水素及び/又は含酸素有機化合物を還元剤とし
て添加して窒素酸化物を還元除去する排ガス浄化材にお
いて、第一の触媒と第二の触媒を混合して用い、前記第
一の触媒が多孔質の無機酸化物に活性種である銀又は銀
酸化物0.2〜15重量%(元素換算値)、銅酸化物
0.01〜2重量%(元素換算値)を担持してなり、前
記第二の触媒が多孔質の無機酸化物に活性種であるPt、
Pd、Ru、Rh、Irからなる群より選ばれた少なくとも1種
の元素0.02〜5重量%を担持していることを特徴と
する排ガス浄化材。
5. A nitrogen oxide is obtained by externally adding a hydrocarbon and / or an oxygen-containing organic compound as a reducing agent to a combustion exhaust gas containing nitrogen oxide and oxygen in a larger amount than the theoretical reaction amount for coexisting unburned components. In an exhaust gas purifying material for reduction and removal, a first catalyst and a second catalyst are mixed and used, and the first catalyst is silver or silver oxide 0.2 to 15 which is an active species of a porous inorganic oxide. Wt% (elemental conversion value), 0.01 to 2% by weight of copper oxide (elemental conversion value) are carried, and the second catalyst is Pt which is a porous inorganic oxide and is an active species.
An exhaust gas purifying material, which carries 0.02 to 5% by weight of at least one element selected from the group consisting of Pd, Ru, Rh, and Ir.
【請求項6】 請求項4又は5に記載の排ガス浄化材に
おいて、前記多孔質無機酸化物が、第一の触媒ではγ−
アルミナ又はアルミナ系複合酸化物で、第二の触媒では
アルミナ、チタニア、ジルコニアのいずれか又はその内
の二つ以上の複合酸化物であることを特徴とする排ガス
浄化材。
6. The exhaust gas purifying material according to claim 4, wherein the porous inorganic oxide is γ-in the first catalyst.
An exhaust gas purifying material, which is alumina or an alumina-based composite oxide, and the second catalyst is any one of alumina, titania, and zirconia, or two or more composite oxides thereof.
【請求項7】 窒素酸化物と、共存する未燃焼成分に対
する理論反応量より多い酸素とを含む燃焼排ガスに外部
から炭化水素及び/又は含酸素有機化合物を還元剤とし
て添加して窒素酸化物を還元除去する排ガス浄化材にお
いて、排ガス流入側から流出側に順に第一、第二、第三
の触媒を有し、前記第一の触媒が多孔質の無機酸化物に
活性種である銀又は銀酸化物0.2〜15重量%(元素
換算値)、銅酸化物0.01〜2重量%(元素換算値)
を担持してなり、前記第二の触媒が多孔質の無機酸化物
に活性種である金0.02〜5重量%を担持してなり、
前記第三の触媒が多孔質の無機酸化物に活性種であるP
t、Pd、Ru、Rh、Irからなる群より選ばれた少なくとも
1種の元素0.02〜5重量%を担持していることを特
徴とする排ガス浄化材。
7. A nitrogen oxide is obtained by externally adding a hydrocarbon and / or an oxygen-containing organic compound as a reducing agent to a combustion exhaust gas containing nitrogen oxide and oxygen in a larger amount than the theoretical reaction amount for coexisting unburned components. In the exhaust gas purifying material for reduction and removal, the first, second, and third catalysts are sequentially provided from the exhaust gas inflow side to the outflow side, and the first catalyst is silver or silver that is an active species in the porous inorganic oxide. Oxide 0.2 to 15% by weight (elemental conversion value), Copper oxide 0.01 to 2% by weight (elemental conversion value)
And the second catalyst carries 0.02 to 5% by weight of gold, which is an active species, on the porous inorganic oxide.
The third catalyst P is an active species for the porous inorganic oxide.
An exhaust gas purifying material, which carries 0.02 to 5% by weight of at least one element selected from the group consisting of t, Pd, Ru, Rh, and Ir.
【請求項8】 窒素酸化物と、共存する未燃焼成分に対
する理論反応量より多い酸素とを含む燃焼排ガスに外部
から炭化水素及び/又は含酸素有機化合物を還元剤とし
て添加して窒素酸化物を還元除去する排ガス浄化材にお
いて、第一の触媒、第二の触媒及び第三の触媒を混合し
て用い、前記第一の触媒が多孔質の無機酸化物に活性種
である銀又は銀酸化物0.2〜15重量%(元素換算
値)、銅酸化物0.01〜2重量%(元素換算値)を担
持してなり、前記第二の触媒が多孔質の無機酸化物に活
性種である金0.02〜5重量%を担持してなり、前記
第三の触媒が多孔質の無機酸化物に活性種であるPt、P
d、Ru、Rh、Irからなる群より選ばれた少なくとも1種
の元素0.02〜5重量%を担持していることを特徴と
する排ガス浄化材。
8. A nitrogen oxide is obtained by externally adding a hydrocarbon and / or an oxygen-containing organic compound as a reducing agent to a combustion exhaust gas containing nitrogen oxide and oxygen in a larger amount than the theoretical reaction amount for coexisting unburned components. In an exhaust gas purifying material for reduction and removal, a first catalyst, a second catalyst and a third catalyst are mixed and used, and the first catalyst is silver or silver oxide in which a porous inorganic oxide is an active species. 0.2 to 15% by weight (elemental conversion value) and 0.01 to 2% by weight of copper oxide (elemental conversion value) are carried, and the second catalyst is a porous inorganic oxide which is an active species. 0.02-5% by weight of certain gold is supported, and the third catalyst is Pt, P which is an active species in the porous inorganic oxide.
An exhaust gas purifying material, which carries 0.02 to 5% by weight of at least one element selected from the group consisting of d, Ru, Rh, and Ir.
【請求項9】 請求項7又は8に記載の排ガス浄化材に
おいて、前記多孔質無機酸化物が、第一の触媒ではγ−
アルミナ又はアルミナ系複合酸化物で、第二の触媒では
アルミナ、チタニア、酸化亜鉛、酸化マグネシウムのい
ずれか又はその内の二つ以上からなる複合酸化物で、第
三の触媒ではアルミナ、チタニア、ジルコニアのいずれ
か又はその内の二つ以上の複合酸化物であることを特徴
とする排ガス浄化材。
9. The exhaust gas purifying material according to claim 7, wherein the porous inorganic oxide is γ-in the first catalyst.
Alumina or an alumina-based composite oxide, the second catalyst is any one of alumina, titania, zinc oxide, magnesium oxide or a composite oxide composed of two or more thereof, and the third catalyst is alumina, titania, zirconia. 2. An exhaust gas purification material, characterized in that it is any one of the above or two or more complex oxides therein.
【請求項10】 請求項1〜9のいずれかに記載の排ガ
ス浄化材において、前記浄化材は前記各触媒をセラミッ
クス製又は金属製の3次元構造体の表面にコートしてな
ることを特徴とする排ガス浄化材。
10. The exhaust gas purifying material according to claim 1, wherein the purifying material is formed by coating the surface of a ceramic or metal three-dimensional structure with each of the catalysts. Exhaust gas purification material.
【請求項11】 請求項1〜9のいずれかに記載の排ガ
ス浄化材において、前記各触媒の多孔質無機酸化物はそ
れぞれペレット状又は顆粒状であることを特徴とする排
ガス浄化材。
11. The exhaust gas purifying material according to any one of claims 1 to 9, wherein the porous inorganic oxide of each catalyst is in the form of pellets or granules.
【請求項12】 窒素酸化物と、共存する未燃焼成分に
対する理論反応量より多い酸素とを含む燃焼排ガスから
窒素酸化物を除去する排ガス浄化方法において、請求項
1〜11のいすれかに記載の排ガス浄化材を用い、前記
排ガス浄化材を排ガス導管の途中に設置し、前記浄化材
の上流側で炭化水素及び/又は含酸素有機化合物を添加
した排ガスを、150〜650℃において前記浄化材に
接触させ、もって前記排ガス中の有機化合物との反応に
より前記窒素酸化物を除去することを特徴とする排ガス
浄化方法。
12. An exhaust gas purification method for removing nitrogen oxides from a combustion exhaust gas containing nitrogen oxides and oxygen in an amount larger than the theoretical reaction amount with respect to coexisting unburned components, and the method according to claim 1. Of the exhaust gas purifying material, the exhaust gas purifying material is installed in the middle of the exhaust gas conduit, and the exhaust gas to which a hydrocarbon and / or an oxygen-containing organic compound is added upstream of the purifying material at 150 to 650 ° C. And a nitrogen oxide is removed by a reaction with an organic compound in the exhaust gas, thereby purifying the exhaust gas.
JP5259126A 1993-09-22 1993-09-22 Waste gas purifying material and method for purifying waste gas Pending JPH0788377A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP5259126A JPH0788377A (en) 1993-09-22 1993-09-22 Waste gas purifying material and method for purifying waste gas

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5259126A JPH0788377A (en) 1993-09-22 1993-09-22 Waste gas purifying material and method for purifying waste gas

Publications (1)

Publication Number Publication Date
JPH0788377A true JPH0788377A (en) 1995-04-04

Family

ID=17329686

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5259126A Pending JPH0788377A (en) 1993-09-22 1993-09-22 Waste gas purifying material and method for purifying waste gas

Country Status (1)

Country Link
JP (1) JPH0788377A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100355488C (en) * 2003-05-07 2007-12-19 韩国高化环保技术有限公司 Catalytic process for nitrogen oxides reduction by multi-injection and use thereof
JP2014069151A (en) * 2012-09-28 2014-04-21 Daihatsu Motor Co Ltd Catalyst for purifying exhaust gas

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100355488C (en) * 2003-05-07 2007-12-19 韩国高化环保技术有限公司 Catalytic process for nitrogen oxides reduction by multi-injection and use thereof
JP2014069151A (en) * 2012-09-28 2014-04-21 Daihatsu Motor Co Ltd Catalyst for purifying exhaust gas

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